Garden with Insight
Garden with Insight v1.0 Help: cycling
Nutrient cycling is the movement of certain elements through different forms in the soil. The reason we
call it nutrient cycling in the soil is that most elements tend to move repeatedly through their
forms over and over.
If you think of the soil as like your body, following nutrient cycling for an element like N or P is like
following the flow of oxygen atoms through your body. You breathe air with oxygen (O2) molecules in it,
and the oxygen is taken out of the air in your lungs and attached to large hemoglobin molecules in your
blood, then the hemoglobin molecules are distributed to your cells, then the oxygen is removed from the
hemoglobin and incorporated in carbon dioxide during respiration,
then the CO2 is dumped in your lungs, and finally the CO2 is breathed out into the air again. The oxygen
atoms were cycled through different forms (O2, hemoglobin, CO2 ) as they passed through your body.
Some elements pass through forms in a similar way in the soil.
Nutrient cycling in the soil depends on mineral creation (by tectonic movement, mineral depositing, and
volcanic flow), mineral weathering (by rain and wind, freezing and
thawing), and the actions of living creatures. Without life, nutrient cycling would continue but would be
radically different. Living organisms take up nutrients and immobilize them (make them unavailable),
then return the nutrients to the system (usually in another form) when they die and decompose.
For example, nitrogen cycles between gaseous N2 (which this simulation does not model), nitrate (NO3-), nitrite (NO2-, which this simulation does not model),
ammonium (NH4+), nitrogen held (immobilized) in live plant matter and soil microbes, and nitrogen in organic compounds in decomposing dead plant
and microbial matter.
How it works: